The glycemic index (GI) is a measure of how a single food will raise
your blood glucose level and it’s a great way to separate good carbs from bad
ones. A food that’s highly glycemic will be digested quickly and is absorbed
immediately, sending your blood sugar level sky-high. The problem is that you
crash quickly and end up feeling sluggish.
If you eat the same portion of a low-glycemic food, your body has to
work harder to break it down. The benefit is that the sugar from the food will
released into the bloodstream more slowly, giving you steady energy over a
longer period.